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CONNECTICUT 

AGRICULIURIL  EXPERIMENT  STATION 

NEW     HAVEN,    CONN. 


BULLETIN    148,    MARCH,   1905. 


The  Preparation  of  Tobacco  Seed. 

By  a.  D.  Shamel, 

Of  the  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture,  in 
cooperation  with  the  Connecticut  Agricultural  Station,  New  Haven. 


It  has  been  proved  by  exact  experiment,  regarding  many 
kinds  of  agricultural  seeds,  that  the  seed  which  is  heaviest  (not 
necessarily  the  largest  or  having  the  greatest  specific  gravity) 
produces  more  vigorous  and  productive  plants  than  lighter  seed. 

This  is  partly  because  the  heavy  seed  has  the  most  perfect 
embyro  or  plantlet  in  it  and  the  largest  supply  of  available  plant 
food  to  support  the  seedling  until  it  has  developed  roots  and 
leaves  so  as  to  feed  itself. 

One  of  the  causes  of  freak  tobacco  plants,  that  is,  such  as  top 
out  prematurely  or  differ  in  shape  and  quality  of  leaf  from  the 
bulk  of  the  crop,  is  the  sowing  of  small  and  light  seed.  In  a 
series  of  extensive  experiments  in  the  Connecticut  valley,  the 
writer  separated  samples  of  seed  of  the  varieties  grown  in  this 
region,  into  light,  medium  and  heavy  grades.  In  all  cases  the 
small  and  light  seed  produced  the  earliest  plants  in  the  seed  bed, 
and  these  plants  when  set  in  the  field  developed  a  large  per- 


centage  of  undesirable  plants  which  are  almost  a  total  loss  to 
the  grower. 

In  crops  like  oats  or  wheat,  if  some  of  the  seed  fails  or 
produces  poor  plants,  the  rest  of  the  plants  stool  out,  and  to 
some  extent  mitigate  the  effect  of  the  use  of  the  poor  seed. 
In  the  tobacco  crop,  however,  there  is  no  compensation  of  this 
kind.  The  sound  plants  grow  no  better  because  others  are 
inferior  or  tmthrifty  and  the  inferior  plants,  mixed  with  the 
others,  damage  the  market  value  of  the  whole. 

Dr.  L.  Trabut  and  other  foreign  experimenters  have  proved 
that  the  plants  grown  from  light  seed  produce  not  only  a  very 
small  yield,  but  the  tobacco  is  of  very  inferior  quality.  The 
light  and  the  small  tobacco  seed  can  be  removed  by  the  grower, 
now,  before  the  seed  is  sowed  in  the  seed  bed,  without  any  extra 
cost.  The  increase  in  yield  and  improvement  in  quality  of  the 
crop  secured  by  this  attention  to  the  seed,  is  pure  profit.  It 
costs  no  more  to  cultivate  and  grow  a  uniform  crop  of  tobacco 
than  a  crop  with  a  large  proportion  of  poor  plants.  Therefore 
it  is  extremely  important  that  the  tobacco  growers  separate 
out  the  light  and  small  seed  before  sowing  the  seed  beds. 

Many  of  the  light  and  inferior  seeds  are  of  the  same  size 
as  the  heavy  and  desirable  seed  and  the  difference  generally 
between  large  and  small  seed  is  slight,  so  that  it  is  not  possible 
to  separate  the  desirable  from  the  undesirable  seed  by  screening 
with  any  kind  of  sieves. 

Some  recommend  water  separation  for  lack  of  a  better 
method.  The  seed  is  thrown  into  a  vessel  of  water  and  when 
the  heaviest  seed  have  sunk  to  the  bottom  the  light  seed  are 
skimmed  off.  This  plan  is  not  a  success  because  the  bubbles 
of  air  in  the  water  prevent  much  of  the  heavy  seed  from  sinking, 
and  the  separation  is  thoroughly  unsatisfactory.  Other  methods 
have  been  recommended,  but  there  are  none  so  simple  and 
practicable  as  the  use  of  the  current  of  air.  A  complete  sepa- 
ration of  the  light  and  small  froin  the  heavy  seed  can  be  made 
by  constructing  a  machine  similar  to  one  designed  and  used  by 
the  writer. 

This  seed  separator  consists  of  a  glass  tube  one  inch  in 
diameter  and  five  feet  long,  and  a  glass  receptacle  for  holding 
the  seed,  having  the  diameter  of  the  long  glass  tube,  and  so 
arrano-ed  with  a  finelv  woven  wire  screen  in  the  bottom  as  to 


— 3— 

hold  the  seed  in  the  receptacle  and  at  the  same  time  freely 
admit  a  current  of  air  directly  into  the  seed.  The  top  of  this 
receptacle  is  fitted  with  a  coupling  into  which  the  long  glass  tube 
can  be  set  and  held  in  place.  The  current  of  air  is  generated  by 
a  common  foot-bellows,  and  regulated  with  a  valve. 

The  seed  to  be  separated  is  poured  into  the  receptacle,  usually 
about  one  to  two  ounces  at  a  time,  the  glass  tube  set  in  place, 
and  a  current  of  air  pumped  into  the  seed.  The  lightest  seed 
and  the  chaff  are  first  blown  out  of  the  tube,  and  next  the 
small  seed.  Small  seeds  of  the  same  character  as  the  larger 
seeds  have  proportionally  more  surface  than  the  larger,  con- 
sequently the  small  as  well  as  the  light  seed  is  removed  by  this 
machine. 

No  doubt  great  improvements  will  be  made  in  the  machines 
for  this  purpose.  Already  Mr.  D.  P.  Cooley  of  Granby,  Conn., 
who  is  cooperating  with  us  in  the  improvement  of  Havana 
seed  tobacco  by  breeding  and  seed  selection,  has  designed  a 
machine  which  is  simple  and  practical.  Mr.  Cooley  has  sepa- 
rated several  bushels  of  seed  in  the  last  few  weeks,  and  it  has 
been  found  in  these  tests  that  a  lot  of  the  seed  saved  last  fall, 
and  thought  to  be  sound,  was  partially  injured  by  frost  and 
should  not  be  used  for  seed  under  any  circumstances. 

Heavy  seed  produces  large,  healthy,  uniform  and  well-devel- 
oped plants.  The  seed  separated. in  the  Connecticut  valley  this 
season  shows  that  the  seed  that  will  be  used  for  sowing  con- 
sists of  about  one-half  of  light,  undesirable  seed.  If  this  seed 
is  separated  out  and  only  the  heavy  seed  used  for  sowing,  it 
will  mean  the  addition  of  thousands  of  dollars  to  the  value  of 
the  coming  crop.  There  is  no  grower  who  can  afford  to  grow 
weak,  variable,  freak  plants  from  light  seed,  when  a  little  time, 
with  no  other  expense,  will  enable  him  to  get  rid  of  a  large 
proportion  of  these  undesirable  plants.  There  are  about  500,000 
tobacco  seeds  in  an  ounce.  The  enormous  quantities  of  seed 
used  to  sow  the  seed  beds  is  sufficient  evidence  that  a  large 
proportion  of  the  seed  used  is  poor  in  vitality  and  quality.  This, 
poor  seed  can  easily  and  practically  be  gotten  rid  of  by  using  a 
seed  separator. 

A  large  number  of  growers  have  already  separated  their 
tobacco  seed  this  sedson,  and  tested  the  vitality  of  the  heavy 
seed.     In  every  case  reported  so  far,  the  growers  have  found 


that  the  heavy  seed  has  sprouted  exceptionally  well,  and  they 
are  surprised  and  thoroughly  satisfied  with  the  results  of  the 
seed  separation. 

A  thin  sowing  of  heavy  seed  in  the  bed  will  no  doubt  yield 
as  many  or  more  sound  plants  than  the  usual  sowing  of  unsepa- 
rated  seed. 

Separate  the  Seed.  Grow  this  Year's  Crop  from  the 
Heaviest  and  Best  Seed  which  You  Have. 


The  Agricultural  Station  hopes  within  a  few  days  to  have  a  sepa- 
rating machine  either  at  the  Station  or  at  the  farm  of  Mr.  J.  A. 
DuBon,  of  Poquonock,  for  the  use  of  growers  w^ho  do  not  find  it 
convenient  to  have  their  seed  separated  elsewhere. 


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Connecticut 

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